As the UK heatwave intensifies, with temperatures forecast to reach 40C this week, a simple DIY hack using two household items can turn an ordinary fan into a makeshift air conditioning unit. The method, shared by Katie Mortram on Good Housekeeping, involves freezing a one-litre water bottle or four-pint milk bottle and placing it in front of an electric fan.
How the DIY Air Conditioner Works
Katie Mortram filled a bottle 75% full with water and froze it. Once solid, she placed the bottle in a shallow tray to catch condensation, covered it with a damp cloth, and positioned it directly in front of a fan. The fan then blows air over the ice, creating a chilled breeze.
Mortram described the experience: "When the time came to remove the bottle from the freezer, it was filled to the brim with ice. The water had expanded to the lid and the bottom of the packaging had even been pushed out by the pressure. Thankfully, it hadn't cracked the packaging, but this did make standing it upright near impossible."
She noted that within two hours, the effect was significant: "On leaving the bedroom, the hallway felt stuffy and stagnant, whereas the bedroom had a tranquil breeze as the chilled air circulated the room."
Effectiveness and Limitations
Mortram confirmed that the homemade unit made the room feel considerably cooler than simply opening a window. However, the ice melted completely within four hours. Despite this, she noted that four hours of cooling can make a world of difference during the hottest parts of the day.
She added: "While I had what I needed at home, this DIY air con wasn't entirely free to build. There was the energy required to freeze the water, and the energy needed to run my fan (which was upped over the four hours). While it's a limited quick fix, I can confirm that this method does work when needed."
Safety Warnings
There are important safety considerations. The tray of ice or water should be placed at least 30cm away from the fan to avoid electrical hazards if the fan is tipped over. Additionally, the NHS warns that if indoor temperatures exceed 35C, fans should not be directed straight at the body, as they can circulate air hotter than skin temperature, accelerating dehydration. Instead, aim the fan away from your body to cool the surrounding air.
The Met Office has issued a rare red weather warning for extreme heat across central and southern England and Wales on Wednesday, June 24, and Thursday, June 25. The current highest June temperature record of 35.6C, set in Southampton in 1976, is expected to be surpassed this week.
